I voted Fumagalli. Maybe it makes me a homer, but here's my case.
He's a bigger part of the offense (targeted 24.7 percent of the time to Gesicki). We have a good indication this isn't because he's been fed the ball short because his catches keep UW ahead of or move the chains 52.2 percent of the time, compared to 47 for Gesicki. That also comes through with the fact Troy is better on yards per target, 7.7 to 7.3, despite the fact Gesicki catches 73.9 percent of balls thrown his way to 64.2 for Troy. I give bonus points for the fact UW's third-down passing was mostly throw to 81, and UW was a very good 3rd down team despite being a middling third-down running team (from the numbers, I get the sense Gesicki was used often as a short ball/screen guy, but that could just be a quirk). Throw in the fact Fum is generally regarded as a better blocker (I think?) and seemed cut and dried on my end.
The Iowa kid is interesting. He blows the other two away in yards per catch and target. He's a really big play guy, granted his catch rate is below 50 percent. Seems like a good deep target. I dunno where you put a big-play guy whose blocking is considered sub-par. It's a weird one to slot.